In the App itslef there is an upgrade button. I think if you upgrade from there it lets you buy it from the market... I'm guessing if you do it through that update button then you won't get the double app issue.
Mixed reviews on this free app of the day. For instance, here's a review on Amazon from earlier today.
Installed, found out it was a "limited functionality" app without a paid "upgrade". Now I have can't completely uninstall it. Could contain malware. At least was able to force stop it. Was still apparently running after attempted uninstallAnd that's not the only negative review. Also, the version number is lower than what comes on the Bionic, which may/may not be relevent if they are really two different versions.
I dunno - think I am passing on this one.
There's a couple of ways to fix that without rooting. You can use folders (or Apps Organizer) if you want to create an Office spot on your phone. Or, and I haven't tried this, you can create a folder inside the app drawer, label it something like "Apps I Use" and stick the ones you want in there. If you use Go Launcher or Launcher Pro+ you can hide the built in version from showing up in the apps drawer.